CN105665878A - Space triangle swing welding method for welding arc-shaped welding seam through welding robot - Google Patents

Abstract

The invention relates to the field of robot welding, and provides a space triangle swing welding method for welding an arc-shaped welding seam through a welding robot.The method includes the steps that a robot welding gun conducts continuous space triangle swinging in the direction of the arc-shaped welding seam and unceasingly moves forwards, and therefore triangle swing welding of the space arc-shaped welding seam is achieved.According to the method, interpolation planning is conducted on a movement inner core upper layer, the space welding route of the arc-shaped welding seam is fitted through a straight line, the algorithm is simple, and universality is high.The method is suitable for triangle swing welding of the space arc-shaped welding seam between a cylinder and a flat plate, the use flexibility is high, and the method is suitable for space arc-shaped triangle swing welding of the arc welding robot and can also be used for other welding devices capable of moving linearly.

Description

A kind of space triangular pendulum soldering method of welding robot welding arch welded joint

Technical field

The present invention relates to the pendulum soldering method of a kind of welding robot arch welded joint, specifically say the space triangular pendulum soldering method relating to a kind of welding robot welding arch welded joint.

Background technology

Welding robot does not require nothing more than the welding that can be used for straight line and arch welded joint, bigger at weld seam or often use pendulum weldering under special welding process requirement. Pendulum weldering refers to that welding torch periodically swings with special angle along bead direction and welds, and to increase bead width, thus improving a kind of welding method of weld strength and welding efficiency, it has been obtained for being widely applied in automatic welding equipment. Pendulum weldering can be divided into sawtooth pendulum weldering, sinusoidal pendulum, three angle swing welderings and circular pendulum weldering by the shape according to pendulum weldering arc manipulation. Three angle swing welderings refer to that torch tip does continuous print triangular motion along welding direction, and constantly along welding direction feeding, thus realizing swinging a kind of welding manner of welding, it has a wide range of applications in welding procedure.

Chinese patent application 201310507312.7 discloses the planing method of a kind of arc welding robot biplane swinging arc track, and it determines the biplane swinging arc track of arc welding robot based on the planing method of Time Continuous. First, the posture information of any two points in the starting point of acquisition welding, terminal and two swinging arc planes, then set acceleration time scale ratio, peak acceleration Amax and maximal rate Vmax. Then, the functional relationship of position, origin-to-destination direction and time is obtained by integration, according to SIN function formula, it is determined that the position planning in swinging arc plane; Then through matrixing to, the location point in swinging arc plane is converted the location point under basis coordinates system of robot, thus controlling robot to carry out swinging arc motion. But the direction of feed that the method requires welding gun is necessary for tool coordinates system Z axis positive direction, reduce the motility that user uses; And it is only used for the pendulum weldering of biplanar straight line, exists and uses limitation greatly.

What the article research of soldering method " arc welding robot pendulum " proposed the pendulum weldering of a kind of plane trigonometry realizes method, but it can be only applied to linear type pendulum weldering, the space pendulum soldering method proposed below is only used for straight line pendulum weldering equally, there is significant limitation in the use of welding." the five dot pattern lead-through teachings " mentioned behind to ask for middle interpolated point respectively according to multiple situation, calculates excessively loaded down with trivial details.

Summary of the invention

The goal of the invention of the present invention, is in that the defect overcoming prior art to exist, it is proposed that the space triangular pendulum soldering method of a kind of welding robot welding arch welded joint, has expanded robot and has swung the use occasion of welding, has improved welding efficiency, improve welding procedure.

Arch welded joint three angle swing weldering includes the pendulum weldering of plane circular arc triangle and space circular arc three angle swing weldering. As shown in Figure 1, the both sides referring to arch welded joint are the pendulum weldering of flat sheet to the pendulum weldering of plane circular arc triangle. Shown in space circular arc three angle swing weldering accompanying drawing 2, refer to that the pendulum of the arch welded joint between plane and cylinder welds.

The present invention be employed technical scheme comprise that by realizing goal of the invention, the space triangular pendulum soldering method of a kind of welding robot welding arch welded joint, and its step is as follows:

1, following parameter is determined: welding starting point coordinate P_start(x_s, y_s, z_s), coordinate of ground point P_target(x_t, y_t, z_t) (welding terminal), auxiliary magnet coordinate P_aux(x_a, y_a, z_a), this auxiliary magnet is any point on arch welded joint between welding beginning and end; Auxiliary magnet coordinate P_aux1(x_a1, y_a1, z_a1), this auxiliary magnet is any point on cylindrical outer surface, and the center of circle of arch welded joint is O₀(x0, y0, z0), radius are r; Basis coordinates system of robot initial point is O (0,0,0); The wide L of welding torch amplitude of oscillation H, welding torch pendulum.

2, welding interpolated point P is calculated according to the amplitude of oscillation and pendulum width_i, i=1,2 ... n, wherein, odd number interpolated point (is commonly referred to as welding base plate) in flat sheet, and even number interpolated point is on cylindrical outer surface.

A, determine arch welded jointWelding direction

By welding starting point, impact point and auxiliary magnet positional information, position vector can be obtainedBead direction is determined by two positions vector.

B, calculating weld seam in-plane cosine value

Set welding place plane as M, n_x, n_y, n_zFor weld seam in-plane cosine value. Its normal vector can be obtained by any two vector multiplication crosses on M, obtain after unitization for normal vector

C, calculating weld seam central angle and unit interpolation angle

Weld seam central angle θ, unit interpolation angle θ₀(i.e. arch welded jointInterpolated point P ' in the middle of upper adjacent two_i-1With P '_iBetween corresponding central angle; Middle interpolated point P '_iIt is welding interpolated point P_iTo arch welded jointAs the intersection point point that vertical line obtains). Three position vectors are obtained by the center of circle and welding starting point, impact point, auxiliary magnet If angSA is vectorWith vectorAngle, angAT is vectorWith vectorAngle, angST is vectorWith vectorAngle. The value of angSA, angAT, angST can be obtained by the multiplication formula of vector, then can be obtained the central angle θ corresponding to path of welding by angSA, angAT, angST three's magnitude relationship.

Welding torch pendulum wide L, welding torch amplitude of oscillation H and arc radius r by setting obtain unit interpolation angle θ₀。

D, ask for weld seam welding interpolated point P_i

According to weld seam central angle θ and unit interpolation angle θ₀, calculate torch oscillation frequency n in welding process.

Adopt the Rotation Algorithm of space coordinates, by welding starting point P_startAround by center of circle O₀Unit normal vector rotary insertion supplementary angle α_iObtain P '_iCoordinate figure. Shown in the premultiplication matrix such as formula (1) of space coordinates Rotation Algorithm:

$R=\left[\begin{array}{cccc}C+n_x^2(1-C)& n_x{n}_y(1-C)-n_{z}S& n_x{n}_z(1-C)-n_{y}S& x_0\\ n_x{n}_y(1-C)+n_{z}S& C+n_y^2(1-C)& n_y{n}_z(1-C)-n_{x}S& y_0\\ n_x{n}_z(1-C)-n_{y}S& n_y{n}_z(1-C)+n_{x}S& C+n_z^2(1-C)& z_0\\ 0& 0& 0& 1\end{array}\right]---\left(1\right)$

In formula, C is cos α_i, S is sin α_i, (n_x, n_y, n_z) for the direction cosines value of unit normal vector, (x₀, y₀, z₀) for center of circle O₀Coordinate figure.

Then P '_iThe coordinate figure of (x ', y ', z ') can pass through matrix R premultiplication weld seam starting point P_startCoordinate obtains, as shown in formula (2):

[x ', y ', z ', 1]^T=R [x_s, y_s, z_s, 1]^T(2)

Set proportionality coefficient l₁, arc radius r and amplitude of oscillation H can determine that proportionality coefficient l₁Value, l₁=(r+H)/r, then the welding of the weld seam in flat sheet interpolated point is obtained by formula (3):

Now, it is desirable to the interpolated point on cylinder must at the upper side of welding base plate, and otherwise welding torch can collide with welding workpiece.By welding starting point P_startAnd P_aux1Position vector can be obtainedByAnd normal vectorRelation may determine that direction coefficient k, is shown below:

Wherein,It is abbreviated as It is abbreviated asThen

Then the welding of the weld seam on cylinder interpolated point is obtained by formula (4):

Prior art is all based on three angle swing soldering methods of straight bead, and use occasion is limited, and motility is low. The space pendulum weldering of present invention circular arc weld seam on arbitrary plane suitable in space, uses motility high, expands the use occasion of arc welding robot. The present invention adopts two positions vectorThe method of multiplication cross, determines the direction of rotation of arch welded joint according to multiplication cross result. The present invention is by three position vectorsAngle angSA, angAT, angST, determine the central angle corresponding to arch welded joint according to the magnitude relationship between three. The present invention adopts the thought divided equally to calculate interpolation angle α_i, utilize space coordinates Rotation Algorithm, by weld seam starting point (P_start) interpolated point P ' in the middle of rotating shaft rotary insertion supplementary angle obtains, then calculate welding interpolated point P according to amplitude of oscillation H_i. Rotating shaft is the unit normal vector axle of arch welded joint place plane, and this axle crosses the center of circle of arch welded joint. Welding for space circular arc three angle swing, the present invention passes through another auxiliary magnet P_aux1, by vectorDetermining direction coefficient k with the unit normal vector relation of weld seam place plane, formula (3) obtain the welding interpolated point on cylinder, the interpolated point on welding base plate adopts plane circular arc interpolated point computational methods to obtain.

The present invention carries out interpolation on motion kernel upper strata, utilizes the path of welding of linear interpolation arch welded joint, and algorithm is simple and versatility good; Cannot be only used for circular arc three angle swing of arc welding robot weldering, it is also possible to the welder of rectilinear motion can be carried out in other.

Accompanying drawing explanation

Fig. 1 is welding robot welding arch welded joint plane trigonometry pendulum weldering schematic diagram.

Fig. 2 is welding robot welding arch welded joint space triangular pendulum weldering schematic diagram.

Detailed description of the invention

Below in conjunction with embodiment, the inventive method is described in further detail.

The present embodiment is space circular arc weld seam three angle swing weldering embodiment.

1, following parameter is determined: welding starting point coordinate P_start(901.7880,182.9200,932.7880), coordinate of ground point P_target(901.7880,210.9640,960.6240), auxiliary magnet coordinate P_aux(918.1900,194.9720,948.5460), auxiliary magnet coordinate P_aux1(918.1900,194.9720,1025.4600), the center of circle of arch welded joint is O₀(898.4030,197.3336,946.3114), radius are 20.0523; Basis coordinates system of robot initial point is O (0,0,0); The welding torch amplitude of oscillation 8, welding torch pendulum is wide by 3.

2, welding interpolated point P is calculated according to the amplitude of oscillation and pendulum width_i, i=1,2 ... n, wherein, odd number interpolated point (is commonly referred to as welding base plate) in flat sheet, and even number interpolated point is on cylindrical outer surface.

A, determine arch welded jointWelding direction

By welding starting point, impact point and auxiliary magnet positional information, position vector can be obtainedDetermined that bead direction is counterclockwise by two positions vector.

B, calculating weld seam in-plane cosine value

Set welding place plane as M, n_x, n_y, n_zFor direction cosines value. Its normal vector can be obtained by any two vector multiplication crosses on M, obtain after unitization for normal vector

C, calculating weld seam central angle and unit interpolation angle

The central angle θ that path of welding is corresponding, unit interpolation angle θ₀Three position vectors are obtained by the center of circle and welding starting point, impact point, auxiliary magnetThe value of angSA (1.393798), angAT (1.403967), angST (2.797766) can be obtained by the multiplication formula of vector, then can be obtained the central angle 2.797766 corresponding to path of welding by angSA, angAT, angST three's magnitude relationship.

Put wide by 3, the welding torch amplitude of oscillation 8 by the welding torch set and arc radius 20.0523 obtains unit interpolation angle θ₀It is 0.149749.

D, ask for weld seam welding interpolated point P_i

Central angle θ corresponding to path of welding and unit interpolation angle θ₀, calculating torch oscillation frequency n in welding process is 19. Adopt the Rotation Algorithm of space coordinates, by welding starting point P_startAround by center of circle O₀Unit normal vector rotary insertion supplementary angle α_iObtain P '_iCoordinate figure.

Set proportionality coefficient l₁, arc radius r and amplitude of oscillation H can determine that proportionality coefficient l₁(1.398957), then the welding of the weld seam in flat sheet interpolated point can be obtained by formula (3).

Now, it is desirable to the interpolated point on cylinder must at the upper side of welding base plate, and otherwise welding torch can collide with welding workpiece. By welding starting point P_startAnd P_aux1Position vector can be obtainedByAnd normal vectorRelation may determine that direction coefficient k is for (1). Then the welding of the weld seam on cylinder interpolated point can be obtained by formula (4). Interpolated point is as shown in the table:

Claims (1)

1. a space triangular pendulum soldering method for welding robot welding arch welded joint, its step is as follows:

A, determine following parameter: welding starting point coordinate P_start(x_s,y_s,z_s), coordinate of ground point P_target(x_t,y_t,z_t) (welding terminal), auxiliary magnet coordinate P_aux(x_a,y_a,z_a), this auxiliary magnet is any point on arch welded joint between welding beginning and end; Auxiliary magnet coordinate P_aux1(x_a1,y_a1,z_a1), this auxiliary magnet is any point on cylindrical outer surface, and the center of circle of arch welded joint is O₀(x0, y0, z0), radius are r; Basis coordinates system of robot initial point is O (0,0,0); The wide L of welding torch amplitude of oscillation H, welding torch pendulum;

B, according to the amplitude of oscillation and pendulum width calculate welding interpolated point P_i, i=1,2 ... n, wherein, odd number interpolated point is in flat sheet, and even number interpolated point is on cylindrical outer surface:

A, by two positions vectorDetermine arch welded jointWelding direction;

B, calculating weld seam in-plane cosine value

Set welding place plane as M, n_x,n_y,n_zFor weld seam in-plane cosine value; Its normal vector can be obtained by any two vector multiplication crosses on M, obtain after unitization for normal vector

C, calculating weld seam central angle and unit interpolation angle

Three position vectors are obtained by the center of circle and welding starting point, impact point, auxiliary magnetIf angSA is vectorWith vectorAngle, angAT is vectorWith vectorAngle, angST is vectorWith vectorAngle. The value of angSA, angAT, angST can be obtained by the multiplication formula of vector, then obtained weld seam central angle θ by angSA, angAT, angST;

Welding torch pendulum wide L, welding torch amplitude of oscillation H and arc radius r by setting obtain unit interpolation angle θ₀;

D, ask for weld seam welding interpolated point P_i

According to weld seam central angle θ and unit interpolation angle θ₀, calculate torch oscillation frequency n in welding process;

By matrix R premultiplication weld seam starting point P_startCoordinate obtains middle interpolated point P '_iThe coordinate figure of (x ', y ', z '):

[x′,y′,z′,1]^T=R [x_s,y_s,z_s,1]^T

Wherein:

$R=\left[\begin{array}{cccc}C+n_x^2(1-C)& n_x{n}_y(1-C)-n_{z}S& n_x{n}_z(1-C)-n_{y}S& x_0\\ n_x{n}_y(1-C)+n_{z}S& C+n_y^2(1-C)& n_y{n}_z(1-C)-n_{x}S& y_0\\ n_x{n}_z(1-C)-n_{y}S& n_y{n}_z(1-C)+n_{x}S& C+n_z^2(1-C)& z_0\\ 0& 0& 0& 1\end{array}\right]---\left(1\right)$

In formula, C is cos α_i, S is sin α_i, n_x、n_y、n_zFor the direction cosines value of unit normal vector, x₀、y₀、z₀For center of circle O₀Coordinate figure;

Weld seam welding interpolated point in flat sheet is obtained by following formula:

Wherein: proportionality coefficient l₁, arc radius r and amplitude of oscillation H determine, l₁=(r+H)/r;

Weld seam welding interpolated point on cylinder is obtained by following formula:

Wherein, k is direction coefficient, by position vectorAnd normal vectorRelation determine:

Wherein,It is abbreviated as It is abbreviated asThen